Sandra Melgar, who is being questioned by Harris County homicide detectives, told authorities she blacked out in the bathroom around 1 a.m. with her husband. She said she was tied up in the closet when she woke up.

Family members discovered the pair around 4:40 p.m. when they arrived at the house to help the couple celebrate a wedding anniversary. Relatives entered through an open garage door and came out screaming for neighbors to call police a short time later, witnesses said.

Neighbors speculated that the couple was a victim of a home invasion, but authorities would not elaborate on the scene, motive or cause of death.

The couple has lived in the house about six years, according to county records.